Engine Oil Pressure Dropping for Some Reason
HikerOnlyJohn
Jeeper
- Posts
- 1
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- Location
- Cumming, Georgia, USA
- Vehicle(s)
- 1981 CJ7, 2.8 Cummins, 1983 CJ7, 4.2, 1952CJ3A
Hello Friends, I have a 1983 CJ7 with a freshly rebuilt AMC 258 i6 / 4.2l engine.
The engine runs great, but I have an intermittent problem with my oil pressure.
At idle I have around 35 pounds of oil pressure and when I am moving it is even higher.
The bearings and oil pump are new since the rebuild (about 2,000 miles).
HERE IS MY PROBLEM:
Sometimes when I am sitting at a light or waiting in traffic, my oil pressure will begin to fluctuate and then go to zero. The engine is running fine. I will be sitting with 35 or so pounds of pressure at idle. The oil pressure gauge needle begins to fluctuate and the pressure will drop to zero. If I cut the engine off and then restart it, the pressure goes back to normal. I can also increase the RPM's when the fluctuation begins and this will usually stop the pressure drop.
It seems as if the bypass is opening and letting the pressure go to zero.
Just as a check, I dropped the pan, checked the bearing tolerances and the oil pick up tube to make sure there was no problem. Nothing was wrong. I also installed a new Melling oil pump since I had the pan off anyway just to make sure.
Can someone tell me why this is happening?
Thank you
JW
The engine runs great, but I have an intermittent problem with my oil pressure.
At idle I have around 35 pounds of oil pressure and when I am moving it is even higher.
The bearings and oil pump are new since the rebuild (about 2,000 miles).
HERE IS MY PROBLEM:
Sometimes when I am sitting at a light or waiting in traffic, my oil pressure will begin to fluctuate and then go to zero. The engine is running fine. I will be sitting with 35 or so pounds of pressure at idle. The oil pressure gauge needle begins to fluctuate and the pressure will drop to zero. If I cut the engine off and then restart it, the pressure goes back to normal. I can also increase the RPM's when the fluctuation begins and this will usually stop the pressure drop.
It seems as if the bypass is opening and letting the pressure go to zero.
Just as a check, I dropped the pan, checked the bearing tolerances and the oil pick up tube to make sure there was no problem. Nothing was wrong. I also installed a new Melling oil pump since I had the pan off anyway just to make sure.
Can someone tell me why this is happening?
Thank you
JW
